The Define series is what really brought Fractal Design into the light for PC enthusiasts; we'd even go so far as to say that it’s iconic. However, it's been over three years since the Define R5, and the market has changed a lot. We were quite excited, then, to learn of the Define R6, which launches today for £120 for the standard edition or £135 for the tempered glass edition that we're reviewing here.

Given that the R5 launched for £90, £135 is a pretty big step up, even taking into consideration the weaker pound. However, this is fine by us, at least in principle, as Fractal Design has broadened its case range in recent years, and we've always seen the Define as more of a flagship family. Thankfully, build quality is very good, probably the best we've ever seen from Fractal in fact. The case is reassuringly weighty thanks to abundant metal – the roof now has an all-steel covering, while the plastic front door has an outer brushed aluminium sheet attached. With its scratch-resistant tempered glass side panel, strong steel core chassis, and rubber tipped feet, we're impressed wherever we look.

The Define series has always been about lowering noise, so the classic closed design is no surprise, but as you'll see, the Define R6 is very flexible and can actually be changed into a more open and high-airflow case quite easily, with support for up to nine fans in total. It is supplied with three of Fractal's own Dynamic X2 GP-14 140mm fans, with two mounted as front intakes and one as a rear exhaust.

While the front fans may appear as if they're starved of airflow, large vents down either side of the front panel see that they're not. The solid front panel is also actually a door, which it reversible and comes fitted with noise-dampening material. It opens to reveal a single optical disk drive bay. This is surprise inclusion in 2017, but given that it's covered by the door and removable and the fact that the case still supports numerous fans and large radiators, it doesn't appear to have any downside.

Below the ODD bay is a large grille that comes with a pre-fitted dust filter. The bottom dust filter, which is full-length to cover both fan mounts here as well as the PSU, also pulls out from underneath the door, making it easier to use than those that come out at the back. The roof, meanwhile, moves to Fractal's third-generation ModuVent design, and it's easily the best yet. While solid and sealed by default, a button at the back pops the central section up and allows you to lift it out, exposing a trio of fan mounts beneath. The removed section can then be split in two, leaving you with the steel cover backed by noise-dampening material in one hand and a ventilated cover in the other much like that found behind the front door. The latter is then reattached to the roof with ease, and suddenly you have a porous roof (with full dust protection) through which air from roof-mounted fans can escape from.

The front I/O panel doesn't have a USB 3.1 Gen 2 Type-C header, but for those who want one, Fractal will be launching the compatible Connect D1 front I/O panel, which will include it as well as all the existing buttons and connectors, in Q1 2018. It will come in at $30 excluding taxes with local pricing still to be confirmed. While having it on the case itself would still have been preferable, we recognise that it's not something everyone needs or wants right now, and this method at least gives users the option while saving money for others. That said, installing a new front I/O panel is likely to be a bit of a faff once you've already wired up the existing one. The Define R6 comes in four different colour schemes, and Fractal will have a version of the Connect D1 for each of them.

Something you may have have noticed no mention of is RGB lighting, and Fractal has indeed stuck to its monochrome roots. We've a feeling this could serve it well, and if you do want to add RGB bling to your build, there are endless options for doing so.